Field of Disclosure
The present disclosure relates to a telecommunication method and a telecommunication system. More particularly, the present disclosure relates to a telecommunication method for a user equipment roaming to a visited network and a telecommunication system for controlling the visited network.
Description of Related Art
When the mobile equipment (i.e. the user equipment) roams to different visited networks outside the local network, different visited networks can allocate different internet protocol addresses to the mobile equipment. Further, other ways to communicate with the mobile equipment may be still based on the communication between the local address and the mobile equipment. That is, the mobile equipment utilizes the access point name built in the subscriber identity module (SIM) as the communication interface between the mobile equipment and the gateway GPRS support node (GGSN) of the local network. Hence, even if the mobile equipment roams to the visited network, the data transmission and telecommunication service of the mobile equipment are still routed through the local network.
However, the delay phenomenon of the signal transmission happens between the mobile equipment and other parties due to that all of the communications (such as data receiving and data transmission) are handled by the local network. When the mobile equipment roams to a visited network the routing distance between which and the local network is larger, the delay phenomenon becomes worse. Furthermore, the signal delay varies depending on different routs from the visited network to the local network. Therefore, the real-time application (such as the voice-over-IP (VoIP)) of the conventional telecommunication technology such as the mobile internet protocol (MIP) turns out to be not as well as expected.